1. Field of the Invention
The present invention relates to a lamp device and, more particularly, to a lamp device allowing smooth flow of air currents into an interior thereof for heat dissipating purposes.
2. Description of the Related Art
FIG. 1 shows a conventional lamp device 9 including a housing 91 having an outer periphery with an air inlet portion 911 and an air outlet portion 912. A lighting element 92, a heat dissipating module 93, and a circuit board 94 are mounted in the housing 91, with lighting element 92 coupled to the heat dissipating module 93 and electrically connected to the circuit board 94. When the lighting element 92 generates heat during use, the heat dissipating module 93 draws air into the housing 91 via the air inlet portion 911, and heat can be transferred out of the housing 91 via the air outlet portion 912, providing a heat dissipating effect and prolonging the life of the lamp device. The circuit board 94 includes a plurality of electronic elements 95 between the circuit board 94 and an end of the housing 91 adjacent air inlet portion 911. Due to the heights h of the electronic elements 95, the compartment between the circuit board 94 and the end of the housing 91 for receiving the electronic elements 95 is relatively large, such that the circuit board 94 interferes with the flow of air currents entering the housing 91 via the air inlet portion 911, as shown in FIG. 2. Thus, the air currents can not smoothly flow into the housing 91, leading to reduced heat dissipating effect and shortening of the life of the lighting element 92.
To reduce interference with the flow of the air currents, Taiwan Utility Model Publication No. M339780 entitled “Improved Circuit Board Structure for LED Lamp Device” discloses a circuit board including at least one aperture in an area free of electronic elements and circuits. The aperture extends from a side through the other side of the circuit board, such that the air currents entering the housing can flow smoothly into an interior of the housing via the aperture, enhancing the heat dissipating effect. However, formation of the aperture results in complicated and troublesome procedures for manufacturing the circuit board. Furthermore, the resultant heat dissipating effect is still unsatisfactory, for the circuit board still causes certain interference with the flow of the air currents entering the housing.